More accurate 1024 FFT peak CPU usage estimate

gui/list.html

@@ -1628,7 +1628,7 @@
 		<li><span class=literal>AudioWindowTukey1024</span></li>
 		</ul>
 	</p>
-	<p>1024 point FFT has a peak CPU usage of approx 50% on Teensy 3.1.
+	<p>1024 point FFT has a peak CPU usage of approx 52% on Teensy 3.1.
 		Average usage is much lower.  Future versions might distribute the
 		load more evenly over time....
 	</p>